I think it's not up to us, the peanut gallery, to judge what any particular developer spends their time on. It's worthwhile to Blow, and he is very vocal that he is developing the language for his own use, not for anyone else. If you keep that in mind, maybe some of the choices around how it's being developed will make more sense.
I'm a language implementor myself and just asked for a clear unique selling point of Jai, and guess what, there was indeed one fellow here who didn't question the question, but has personal experience and was able to give me the information I was interested in (see https://news.ycombinator.com/item?id=37369342), without me having to read or listen through dozens of outdated blog posts and presentations. I still think a language specification would be worthwhile, even during early development.
From what I understood from Blow, a specification at this point would only serve to have other people bike shed about syntax, features, etc.
Looking at the explanation you linked, I would say that the author uses the language in a very unidiomatic way (if idiomatic Jai would be a thing :D). It takes a very template focused mindset and uses the features of the language to bastardize and complicate things needlessly (IMHO, as a not game developer). I think my main take away from the language is that it focuses on the way memory is mapped (similarly to how C does it) and less on behaviour associated with that memory.
So for that example, instead of trying to overthink a container that uses a generic behaviour through templated types, it would implement different overloaded functions for each type as needed.
> a specification at this point would only serve to have other people bike shed about syntax, features, etc.
It makes little sense to announce a language with a lot of details over so many years without providing a decent specification. Either the author is interested in feedback, then a specification or language report is the established vehicle among language designers, or he is not interested in feedback, which raises the question why he publishes any details at all.
> It takes a very template focused mindset and uses the features of the language
But as it seems that's a focus point of the language; why otherwise the author would take the effort to even modify structure declarations with compile time expressions.
> that it focuses on the way memory is mapped (similarly to how C does it)
What do you mean by that? And is this really a unique selling point if it is similar to C?
I offered a very bird's eye view of what a newbie understood from the language, not a "unique selling point" because, like I keep failing to make you see, Blow is not trying to "sell it" to anyone.
